High PHD finger protein 19 ​expression predicts inferior prognosis in diffuse large B-cell lymphoma

PHD finger protein 19 (PHF19) is an epigenetic regulator known to be associated with the prognosis of patients in various tumours, while its impact on the prognosis of diffuse large B-cell lymphoma (DLBCL) remains unexplored. This study aimed to investigate the expression and prognostic significance of PHF19 in DLBCL. PHF19 expression was assessed in 192 DLBCL cases using immunohistochemistry. Correlations between PHF19 expression and clinicopathological parameters were analysed. Survival analysis was performed in patients receiving an anthracycline-based regimen with rituximab. The intensity of PHF19 protein expression in DLBCLs was significantly higher than that in normal lymph nodes. PHF19 expression was observed in 175 of 192 (91.1%) DLBCL cases, and 78 cases (78/192, 40.6%) were classified as PHF19 high expression. A high PHF19 expression correlated positively with Ann Arbor stages III-IV. In the cohort receiving an anthracycline-based regimen with rituximab, the 10-year overall survival (OS) rate and progression-free survival (PFS) rate were 86.0% and 58.0%, respectively. Compared with the PHF19 low-expression group, patients in the PHF19 high-expression group demonstrated significantly inferior OS and PFS. The multivariate analysis confirmed that a high level of PHF19 expression was an independent risk factor for inferior PFS, irrespective of Ann Arbor stage, B symptoms, Eastern Cooperative Oncology Group (ECOG) scores, International Prognostic Index (IPI) scores, and germinal centre B-cell (GCB) subtype. In conclusion, PHF19 was frequently expressed in DLBCL and high levels of PHF19 expression predicted an adverse outcome in DLBCL. Furthermore, the internal mechanisms of PHF19 involving proliferation and interactions with other genes need exploration in future studies.